The present invention relates to a mechanism for supporting a magnetic head which records and reproduces data to a magnetic disk. More particularly, this invention relates to a structure of a suspension element for supporting a head slider.
The magnetic head slider has a transducing gap and a magnetic circuit and moves to radially accessing different data tracks on the surface of a rotating magnetic disk at high speed for recording data on the disk or reproducing the recorded data. It is necessary for the head slider to follow the changing topography (surface irregularities) of the rotating disk with keeping a constant floating space to the disk surface, as well as to be positioned at a target track on the surface of the disk at high speed and with high accuracy. For these reasons, the mechanism for supporting the head slider is required to press the head slider against the surface of the disk with an appropriate loading force. Further, the supporting mechanism is required to be flexible in the direction orthogonal to the disk surface, but rigid in the direction parallel to the disk surface.
In addition, there are many factors emitting a vibration in a magnetic disk driving apparatus. For example, a driving mechanism for rotating the magnetic disk, and an actuator assembly for moving the head slider in the radial direction of the disk emit vibrations. Further, the head supporting mechanism receives variant pressing force from the head slider floating on the disk in response to the changing topography of the disk surface. Therefore, the variance of the pressing force to the head supporting mechanism may causes the vibration in a resonant frequency. Accordingly, the head supporting mechanism is required not to give detrimental vibrations to the head slider.
This type of magnetic head supporting mechanism is disclosed in the U.S. Pat. Nos. 3,931,641 and 4,167,765. In these magnetic head supporting mechanism, the head slider is mounted on a flexure including a center tongue and two outer fingers. The flexure is secured to the appex of a suspension element including a triangular load beam section. The load beam section is provided with flanges to form a rigid beam structure. The suspension element is secured to a rigid arm section at its base portion. This head supporting mechanism resiliently supports the head slider closely to the disk surface such that the suspension element is substantially parallel to the disk surface.
Such a conventional magnetic head supporting mechanism permits the head slider to follow the changing topography of the disk. Further, this supporting mechanism presses the head slider with a proper pressure in a direction orthogonal to the disk surface. However, in recording or reproducing operation, the suspension element vibrates in both its longitudinal axial direction and the direction which is orthogonal to the longitudinal axis and parallel to the disk surface due to the aforementioned vibrations. This vibration is directly transmitted to the head slider through the beam structure. In consequence, the head slider also vibrates in directions parallel to the disk surface during the recording and reproducing operation. Namely, the head slider vibrates over a target track and the recording or reproduced signal degrades in quality. Therefore, sufficient width of the track pitch is required to cover the amplitude of the vibration of the slider. Thus, the vibration of the suspension element has been one of the reasors of preventing the increase in the track density of the disk.